class Student2
        attr_accessor :name
        attr_accessor :no
        attr_accessor :gender

        def initialize(name,no,gender)
                @name = name
                @no = no
                @gender = gender
        end

        # 這個方法是實例方法
        def say_hello
                puts @name
        end
        # self表示本身，這個方法是類方法
        def self.nick_name
                return "學生類"
        end
end

#大學生類繼承學生類:<
require Student
class UniversityStudent < Student
        # 重寫父類方法
        def say_hello
                puts "大學生#{@name}"
        end
        def say_english
                p "my english is very good"
        end
end